Results from the past year's work on the responses of single cells in the posterior colliculus of the chinchilla are summarized. Sensitivity of collicular cells appears to be limited by bullar resonances. Isofrequency orientations of electrode penetration run from dorsomedial to ventral in the colliculus. Latency of cells verified to be within the central nucleus of the posterior colliculus can be as long as 55 msec.